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Class / Patent application number

Description

Number of patent applications / Date published

075744000

Noble metal recovered as free metal

40

20090301260

EFFICIENT PROCESS FOR PREVIOUS METAL RECOVERY FROM FUEL CELL MEMBRANE ELECTRODE ASSEMBLIES - A method is provided for recovering a catalytic element from a fuel cell membrane electrode assembly. The method includes grinding the membrane electrode assembly into a powder, extracting the catalytic element by forming a slurry comprising the powder and an acid leachate adapted to dissolve the catalytic element into a soluble salt, and separating the slurry into a depleted powder and a supernatant containing the catalytic element salt. The depleted powder is washed to remove any catalytic element salt retained within pores in the depleted powder and the catalytic element is purified from the salt.

12-10-2009

20130074655

METHOD AND A SYSTEM FOR GOLD EXTRACTION WITH HALOGENS - The invention relates to a method for the extraction of precious metals, using halogens. It has been found that introducing halogens in the reactor in the form of hypohalites rather than free halogens simplified greatly the recycling of halogens by electrolysis. It increases the rate of addition of the halogens and significantly reduces secondary reactions with base metals such as iron. Operating under acidic conditions, the gold recovery has been found as high with hypochlorite as with elemental chlorine, with an active chlorine to ore ratio reduced by a factor of two to five.

03-28-2013

20090293680

Processing of Metal Values from Concentrates - The present invention relates to an improved method for the recovery of metal values, in particular copper and gold, from a metal value-bearing material containing arsenic and/or antimony and a source of sulphate ions, by means of a high temperature pressure oxidation process followed by cyanidation of the resultant high temperature pressure oxidation residue.

12-03-2009

20100024603

REDUCTION OF LIME CONSUMPTION WHEN TREATING REFRACTORY GOLD ORES OR CONCENTRATES - The present invention is directed to a precious metal recovery process in which basic ferric sulphates and/or jarosites are controlled by a number of mechanisms, including control of the oxidation reaction conditions in the first autoclave compartment, hot curing of the autoclave discharge slurry, and/or contacting of the autoclave feed slurry with the hot cured discharge liquid.

02-04-2010

20100116092

PROCESS FOR EXTRACTING GOLD FROM GOLD-BEARING ORE - A process for extracting gold from a gold-bearing ore. The process includes, first, providing a leaching liquor with thiosulfate anion and ethylenediamine. Next, the leaching liquor is contacted with the gold-bearing ore to form a pregnant leach solution including gold dissolved from the gold-bearing ore. Finally, at least part of the gold in the pregnant leach solution is recovered.

METHOD OF LEACHING COPPER AND GOLD FROM SULFIDE ORES - Disclosed is a method of leaching copper and gold from sulfide ores, which includes Process (1) of bringing a first aqueous acidic solution which contains chlorine ion, copper ion and iron ion, but no bromine ion, into contact with sulfide ores under supply of an oxidizing agent, so as to leach copper component contained in the sulfide ores; Process (2) of separating, by solid-liquid separation, a leaching reaction liquid obtained in Process (1), into a leaching residue and a leachate; and Process (3) of bringing a second aqueous acidic solution which contains chlorine ion, bromine ion, copper ion and iron ion, into contact with the leaching residue obtained in Process (2) under supply of an oxidizing agent, so as to leach gold contained in the leaching residue.

METHOD OF RECOVERING SILVER USING ANION-EXCHANGE RESIN - The present invention provides a method of recovering silver safely and efficiently from a chloride or bromide bath containing various metals. Specifically, a method of recovering silver from a hydrochloric acid solution containing alkali and/or alkali earth metal chloride, silver; copper and iron ions, comprising the steps of: (1) bringing the solution into contact with a strong-base anion-exchange resin to adsorb silver; copper, and iron on the anion-exchange resin; (2) then washing the anion-exchange resin with water to remove the adsorbed copper and iron; and (3) then bringing the ion-exchange resin into contact with a hydrochloric acid solution to elute the adsorbed silver, is provided.

PROCESS OF LEACHING GOLD - A process of leaching gold comprising the steps of: a) leaching copper from copper sulfide ore material that contains gold or contains silicate ore containing gold until the copper grade is reduced to 7.9 wt % or less; b) mixing the resulting material having a copper grade of 7.9 wt % or less with a gold leaching solution selected from the group consisting of a first solution containing chloride ions and ferric ions, and a second solution containing chloride ions and iron ions, the iron ions having been oxidized to trivalent ferric ions by air bubbled into the second solution; c) adjusting the pH of the gold leaching solution to 1.9 or less with stirring to leach at least gold in the material into the gold leaching solution by the oxidative activity of the ferric ions contained in the gold leaching solution, wherein the concentration of gold is reduced by selectively removing gold from part or all of the gold leaching solution during gold leaching. This process efficiently leaches at least copper and gold from a copper sulfide ore.

CATALYST REPROCESSING - A process for re-processing of a Fischer-Tropsch catalyst is described comprising the steps of; (i) de-waxing the Fischer-Tropsch catalyst, (ii) subjecting the de-waxed catalyst to hydrometallurgical leaching or extraction to separate catalyst metal or metals from catalyst support material, and (iii) recovering the separated catalyst metal or metals, wherein the de-waxing step is performed using a pressurised near-critical or supercritical fluid under conditions that minimise catalyst metal spinel formation.

METHOD FOR RECOVERING METAL VALUES FROM REFRACTORY SULFIDE ORE - A method for recovering metal values from refractory sulfide ores is provided. The method includes the steps of separating clays and fines from crushed refractory sulfide ore, forming a heap from the refractory sulfide ore, producing a concentrate of refractory sulfide minerals from the separated fines and adding the concentrate to the heap, bioleaching the heap to thereby oxidize iron sulfides contained therein, and hydrometallurgically treating the bioleached ore to recover metal values contained therein.

08-12-2010

20110132147

METHOD FOR THIOSULFATE LEACHING OF PRECIOUS METAL-CONTAINING MATERIALS - Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ lixiviants that include at most only small amounts of copper and/or ammonia and operate at a relatively low pH, reduction of polythionates, inert atmospheres to control polythionate production, and electrolytic solutions which provide relatively high rates of precious metal recovery.

METHOD OF SEPARATING RHODIUM FROM PLATINUM AND/OR PALLADIUM - A method of separating rhodium from platinum and/or palladium includes; chloridizing a raw material including rhodium and at least platinum and/or palladium in chlorine atmosphere and obtaining a soluble salt of platinum and/or palladium; water-leaching chloridized material and dissolving platinum and/or palladium into a solution; filtering the solution; and leaving rhodium in a filtered residue of the solution.

07-22-2010

20100116091

System and Method for Leaching a Metal from a Base Mineral Rock - A system and method for leaching a metal from a base mineral rock includes a closed reactor vessel into which a slurry containing the ground base mineral rock is fed. The interior space of the vessel is then pressurized via an oxygen supply to a pressure P. The slurry is then agitated under pressure P and within the closed reactor vessel for a time “t”. A blower or compressor re-circulates the oxygen through the slurry. The required pressure P and time “t” are effective for obtaining a metal recovery of up to 98% of the total metal available in the base mineral rock. Tests demonstrate that a time “t” in a range of 8 to 14 minutes and a pressure P of 10 to 50 psi is effective for obtaining the desired recovery amount, depending on the concentration of attacking agent used.

05-13-2010

20110259148

Method for Aqueous Gold Thiosulfate Extraction Using Copper-cyanide Pretreated Carbon Adsorption - A gold thiosulfate leaching process uses carbon to remove gold from the leach liquor. The activated carbon is pretreated with copper cyanide. A copper (on the carbon) to gold (in solution) ratio of at least 1.5 optimizes gold recovery from solution. To recover the gold from the carbon, conventional elution technology works but is dependent on the copper to gold ratio on the carbon.

Method for recovering metal from ore - The copper sulfide ore is leached in the halide bath without using a special oxidant but with the use of only air. The copper and gold in the copper sulfide ore can be leached at high leaching ratio.

10-01-2009

20120304828

PROCESS OF LEACHING GOLD - This invention provides a process of leaching gold that can be inexpensively and efficiently carried out without using cyan from the mixture containing sulfur and gold, typically from the material which contains sulfur and gold and is an intermediate product recovered by the flotation method in the hydrometallurgical method.

12-06-2012

20120234138

METHOD OF RECOVERING GOLD FROM DILUTE GOLD SOLUTION - Disclosed is a method of recovering gold from an aqueous solution having a gold concentration of 10 mg/L or lower, using a plurality of extraction apparatuses for bringing the aqueous solution into contact with an extraction agent, arranged to configure a multi-stage extraction process, the method allowing the aqueous solution to continuously flow from the first-stage extraction process to the next-stage extraction process, while recycling the extraction medium used in each stage twice or more times for the extraction process of the same stage, without back extraction and reduction.

09-20-2012

20140096649

ALKALINE AND ACID PRESSURE OXIDATION OF PRECIOUS METAL-CONTAINING MATERIALS - The present invention is directed to a precious metal recovery process in which an acid sulfidic feed material is subjected to acid pressure oxidation and an alkaline sulfidic feed material is subjected to alkaline pressure oxidation, with the discharge slurries from the pressure oxidation processes being combined to reduce neutralization requirements prior to precious metal recovery.

04-10-2014

20120060651

CONTROLLED COPPER LEACH RECOVERY CIRCUIT - The present invention relates generally to a process for controlled leaching and sequential recovery of two or more metals from metal-bearing materials. In one exemplary embodiment, recovery of metals from a leached metal-bearing material is controlled and improved by providing a high grade pregnant leach solution (“HGPLS”) and a low grade pregnant leach solution (“LGPLS”) to a single solution extraction plant comprising at least two solution extractor units, at least two stripping units, and, optionally, at least one wash stage.

03-15-2012

20100132509

METHOD FOR THIOSULFATE LEACHING OF PRECIOUS METAL-CONTAINING MATERIALS - Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ lixiviants that include at most only small amounts of copper and/or ammonia and operate at a relatively low pH, reduction of polythionates, inert atmospheres to control polythionate production, and electrolytic solutions which provide relatively high rates of precious metal recovery.

06-03-2010

20110011216

PROCESS FOR RECOVERING METALS FROM RESINS - A process for recovering metals involving ion exchange comprising the step of recovering metal species from an ion exchange resin by elution of the resin with an eluent system containing (i) a first sulphite component comprising at least one of sulphite and bisulphite ion; and (ii) a second eluting component comprising any species which favours the ion exchange or desorption of a metal species from the resin during elution wherein the presence of the sulphite component (i) increases metal elution efficiency relative to the situation where an eluent comprises the second eluting component alone.

01-20-2011

20140373684

PRECIOUS METALS RECOVERY - Discloses a hydrometallurgical process and system for the recovery of precious metals; specifically palladium, rhodium, and platinum metals, at high purity and with limited waste and environmental fouling.

12-25-2014

20140331822

Process of Leaching Gold - Disclosed is a process of leaching gold that can be inexpensively and efficiently carried out from a mixture containing sulfur and gold, typically from the material containing sulfur and gold that is an intermediate product recovered by the flotation method in the hydrometallurgical method. Specifically, disclosed is a process of leaching gold from the mixture containing elemental sulfur and gold, the process involving combining the mixture containing elemental sulfur and gold and an aqueous solution of hydroxide of one or more of metals of alkali metals and alkaline earth metals, the hydroxides reacting with elemental sulfur to form thiosulfate of alkali and/or alkaline earth metal, and the gold thereby being leached by reaction with the thiosulfate.

11-13-2014

20120103138

METHOD OF OXIDATIVE LEACHING OF SULFIDE ORES AND/OR CONCENTRATES - A method for leaching one or more target metals from a sulfide ore and/or concentrate containing such, the method comprising the steps of: (a) Exposing the ore and/or concentrate to an aqueous solution of chlorine-based oxidising species in which the hypochlorous acid comprises at least 10 mol % of the chlorine-based oxidising species; (b) Allowing and/or facilitating the oxidation of the target metals by the hypochlorous acid, thereby decreasing the pH such that the predominant chlorine-based oxidising species becomes chlorine; (c) Allowing and/or facilitating the oxidation of the target metals by the chlorine; (d) Allowing and/or facilitating the dissolution of the target metals by the solution species formed during the oxidation by hypochlorous acid and/or chlorine; and (e) Passing the pregnant solution produced thereby to a means for metal recovery.

05-03-2012

20090031862

RECOVERY PROCESS FOR PRECIOUS METALS - A recovery process for at least one precious metal contained in an ore, includes: comminuting the ore to obtain particles smaller than a predetermined particle size; separating the particles into at least two groups, each group being characterized by a particle size range; and leaching separately each group of particles with a reagent adapted to dissolve the at least one precious metal.

02-05-2009

20130220079

PROCESS FOR THE RECOVERY OF GOLD FROM AN ORE IN CHLORIDE MEDIUM WITH A NITROGEN SPECIES - A process and system for recovery of gold from an ore having the steps of i) providing the ore containing the gold to be recovered, ii) leaching the ore in an oxidative chloride medium, including a nitrogen species to produce a solution comprising gold; and iii) recovering the gold from the solution. The gold in a preferred embodiment is recovered from refractory and carbonaceous ores.

08-29-2013

20130091990

METHOD FOR RECOVERING PRECIOUS METALS AND COPPER FROM LEACH SOLUTIONS - The present disclosure is directed to a process for recovering a precious metal from a pregnant leach solution using a resin extractant. The precious metal is eluted from the loaded resin using an eluant comprising trithionate. The barren resin is contacted with a sulfide, bisulfide, and/or polysulfide to convert sorbed trithionate to thiosulfate. The desorbed thiosulfate is contacted with an oxidant and converted to trithionate for eluant recycle.

ENHANCED RECOVERY OF GOLD - An improved method for recovering refractory gold from a material comprising treating the material to at least partially remove nitric acid-insoluble lead moieties.

04-19-2012

20140047954

METHOD FOR THIOSULFATE LEACHING OF PRECIOUS METAL-CONTAINING MATERIALS - Processes are provided for recovering precious metals from refractory materials using thiosulfate lixiviants. The processes can employ lixiviants that include at most only small amounts of copper and/or ammonia and operate at a relatively low pH, reduction of polythionates, inert atmospheres to control polythionate production, and electrolytic solutions which provide relatively high rates of precious metal recovery.

02-20-2014

20090019970

PROCESS FOR RECOVERY OF METAL VALUES FROM MATERIALS CONTAINING ARSENIC AND/OR ANTIMONY - A method for the recovery of metal values from a metal value-bearing material containing arsenic and/or antimony and a source of sulphate ions such as sulphide ore or concentrate is disclosed. In one form the method comprises the steps of: (a) providing a feed stream comprising a metal value-bearing material containing arsenic and/or antimony and a source of sulphate ions; (b) subjecting the feed stream to oxidative conditions under elevated temperature and pressure conditions in the presence of at least one component selected to decrease the effective concentration of free acid generated during the pressure oxidation step and promote the formation of pH-stable iron (III) sulphate products, thereby forming a slurry comprising a metal value-containing leach solution and a solid leach residue containing pH-stable iron (III) sulphate products and environmentally stable iron-arsenic and/or iron-antimony products; (c) separating the metal value-containing leach solution from the solid leach residue; (d) recovering the metal value (s) from the metal value-containing leach solution; and (e) recovering precious metal values, if present, in the solid leach residue by cyanide leaching.

01-22-2009

20120227545

AQUEOUS LEACHING PROCESS FOR RECOVERY OF PRECIOUS METALS WITH ADDITION OF DI-THIOOXAMIDE LIGAND - This invention relates to a process for the recovery of precious metal/s from a precious metal-containing material in an aqueous leach slurry or solution. The process includes the step of contacting the precious metal/s in the leach slurry or solution with a ligand selected from dithiooxamide (rubeanic acid), or a substituted dithiooxamide. The leaching of PGMs, gold and silver from their ores using the ligand of the present invention may take place under aqueous alkaline conditions, avoiding both corrosive acidic conditions and the use of cyanide.